Automatic electric self-synchronizing polarizing windows

ABSTRACT

A FIRST POLARIZING WINDOW ELEMENT IS POSITIONED OVER A WINDOW OPENING IN THE WALL OF AN AIRCRAFT CABIN AND FIXEDLY ATTACHED TO THE CABIN WALL. A SECOND POLARIZING WINDOW ELEMENT IS POSITIONED OVER THIS OPENING IN OVERLYING RELATIONSHIP TO THE FIRST ELEMENT, THIS SECOND ELEMENT BEING SUPPORTED FOR ROTATION RELATIVE TO THE FIRST. THE ROTATABLE ELEMENT IS CIRCULAR AND IS ROTATABLY DRIVEN BY MEANS OF A FRICTION ROLLER DRIVE WHICH ENGAGES THE RIM THEREOF. THE AMOUNT OF LIGHT ENTERING THE CABIN THROUGH THE WINDOW IS CONTROLLED BY ROTATING THE ROTATABLE ELEMENTS RELATIVE TO THE FIXED ELEMENT, EITHER BY MEANS OF A MANUAL CONTROL OR IN RESPONSE TO A LIHT SENSITIVE DETECTOR.

June 13, 1972 A. WEISS 3,669,526

AUTOMATIC ELECTRIC SELF-SYNCHRONIZING POLARIZING WINDOWS Original FiledAug. 11, 196'? 4 Sheets-Sheet'l 1? I 22 I 201 L n 2 f J 16 [it zZd June13, 1972 A. WEISS 3,669,526

AUTOMATIC ELECTRIC SELF-SYNCHRONIZING POLARIZING WINDOWS Original FiledAug. 11, 1967 4 Sheets-Sheet 2 ll ra. 1?.

I/vvEN Toe Hz. w/v 11 2/55 June 13, 1972 A. WEISS 3,569,526

SELF'SINCIIRQNIZING POLARIZING WINDOWS AUTOMATIC ELECTRIC 4 Sheets-Sheet3 Original Filed Aug. 11, 1967 .ZDvvsxv 7-0/2 4 V/N 7155/55 M w zgwflrrolemeeb".

AUTOMATIC ELECTRIC SELF-SYNCHRONIZING POLARIZING WINDCWS Original FiledAug. 11, 1967 A. WEISS June 13, 1972 4 Sheets-Sheet l OVERFUDE PASSCONTROL INVENTO2 21. w/v 772/55 7/1429 #4 TOE/V5945.

United States Patent Int. Cl. G021) 27/28 U.S. Cl. 350-159 ClaimsABSTRACT OF THE DISCLOSURE A first polarizing window element ispositioned over a window opening in the wall of an aircraft cabin andfixedly attached to the cabin wall. A second polarizing window elementis positioned over this opening in overlying relationship to the firstelement, this second element being supported for rotation relative tothe first. The rotatable element is circular and is rotatably driven bymeans of a friction roller drive which engages the rim thereof. Theamount of light entering the cabin through the window is controlled byrotating the rotatable element relative to the fixed element, either bymeans of a manual control or in response to a light sensitive detector.

REFERENCE TO RELATED APPLICATION This application is a continuation ofapplication Ser. No. 660,115 filed Aug. 11, 1967 for Automatic ElectricSelf-Synchronizing Windows, now U.S. Patent No. 3,5521,300.

This invention broadly relates to improving passenger comfort,psychlological well-being, safety, and convenience, as well as relievingaircraft maintenance conditions through the use of automatic electricself-synchronizing polarizing windows. Although this invention is moredirectly aimed at aircraft usage, it is also intended towards buildings,dwellings, ships, other vehicles, and more importantly, aerospacevehicles.

By electrically rotating one polarizing filter with respect to another,light transmission from a light source to the interiors of any of theaforementioned vehicles or structures may be infinitely controlled byautomatic and electrical means. Basic intent is to reduce glare andeliminate shades, drapes, curtains, etc. through automatic andelectrical combined means and provide a practical polarizing windowsystem as is herein described.

The broad concept of variable density windows was initiated by E. H.Land and described in United States Patent No. 2,311,840, granted himFeb. 23, 1943. Other polarizing windows are revealed in United StatesPatents Nos. 2 423,321 and 2,464,954, granted to S. C. Hurley, Jr. andL. A. Werth, respectively, on July 1, 1947 and Mar. 22, 1949, to whichreference may be made for a more complete description.

The basic intent of this invention as previously outlined, isaccomplished by novel means of achieving the goals set forward herein,by the use of the latest state-ofthe-art devices and materials, whichare utilized in making it a more feasible device for more practicalpresent and future application.

Amongst the advantages of this invention is the capability of preventingpassage of ultra-violet rays through the variable density windows or tothe polarizing elements. Ultra-violet rays from the sun will normallyfade the polarizing elements within a short time, thus making themuseless and impractical. This invention eliminates this problem ofultra-violet ray damage in such a manner so as to protect the polarizingelements as well as protecting interior materials and fabrics fromfading, which additionally enhances its practicality, and is applicableregardless of the polarizing attitude of the polarizing filters.

During flight, airline passengers are psychologically protected from theclasutraphobic effect of closed shades, since some exterior light isalways visible, even in the minimum light transmittance attitude of thepolarizers which shall hereinafter be known as the Dark position.

This invention has the capability of being electrically adjusted to thearbitrated comfort of neighboring passengers in the event one wishes tosleep or watch T.V., while the other is desirous of gazing out thewindow. This is accomplished by the passenger control switch which maybe normally spring loaded off, and pressed to actuate one or morewindows to either the Dark position, maximum light transmittanceposition (hereinafter known as the Light position) or any infinitelydesired light transmittance level between, and remain stationary at thatlevel. The passengers may also have an on-off type switch with anintegral potentiometer control for the Automatic function.

The intent of the Automatic function is to provide an automatic overridewhich causes the windows to go dark when external light exceeds theminimum glare level potentiometrically selected. When external glaredrops below the selected level again, the windows automatically returnto the Light position for further passenger readjustment to desiredlevels.

It is presumed that within a building, aircraft, etc., illumination willnot vary considerably, rapidly, or constantly as a result of externallight changes. Likelyhood of frequent adjustment is not anticipated.However, to satisfy requirements arising wherein a constant lighttransmittance is desired, it is intended that this invention will coversame by slight mechanical and electrical modification. The Automaticfeature is provided as a convenience allowing one to be preoccupied withsomething else while the windows make their own adjustment.

An Automatic feature is well described in general as applied topolarizing devices in United States Patents Nos. 2,417,883, granted toS. Oschin, Mar. 25, 1947; 3,159,844, granted to R. C. Haboush, Dec. 8,1964; 2,548,230 granted to C. P. Molyneux, Apr. 10, 1961; 2,755,700,granted to G. Ljungstrom, July 24, 1956; 2,134,414, granted to A. S.Norcross, Oct. 25, 1938; 2,453,693, granted to C. W. Armstrong et a1.Nov. 16, 1948; and Nos. 2,423,321 and 2,423,322, granted to S. C.Hurley, Jr., July 1, 1947.

It may be noted that previous inventions olier a light polarizing means,automatic in nature, which respond to a light activated device. However,none of these offers:

(1) A complementary electrical feature for achieving infinitely desiredstationary positions between Dark and Light,

(2) utilize solid state circuitry, or

(3) have a temperature stabilized circuit for preventing drift in relayoperation.

Stable reaction of the circuit to temperature variation is equally asimportant as it is to light intensity variation, particularly in fastrising aircraft or constantly rotating space vehicles.

The pilot and hostess may have an override switch which would allowthem. to take control from the passengers during an emergency, or todarken an entertainment center showing movies, or as a signal device, orat any other time when its function would be utilizable.

This invention eliminates the need for shades, which are constantlybeing ripped, torn, soiled, and broken, presenting a high maintenanceproblem for the airlines.

One object of this invention is to provide a self-synchronizing featurewhen two or more polarizing windows are used in conjunction with eachother. The desirability of keeping two or more polarizing windows insync on the sides of an airplane, building structure, or other vehicle,is often needed for practical reasons as well as for purely aestheticones. By In Sync, we are referring to the capability of maintaining thesame level of light transmittance through two or more polarizingwindows, remote from each other at all times regardless of the lighttransmittance desired, either electrically or automatically.

Another objective is to provide a spring loaded mount to provide forwear on the rotating polarizing filter. Shock mounting is particularlyadvantageous for this device with respect to shock, vibration, and otherinertial forces imposed on aircraft and other moving vehicles. In thecase of buildings and other structures, shock mounting wards off most ofthe ravages of earthquakes and sonic booms, partly due to a change inthe resonant frequency of the windows.

An added feature is a detachable wiper blade, which may be installed oneither the rotatable polarizing filter, an adjacent window, or both, toremove condensation during the rotating polarizing action, if conditionsnecessitate its usage. The wiper blade is of particular value on outerspace vehicle windows, which are constantly encountering this problem.

An important objective is the automatic function, initiated by controlswitch selection and one or more light sensing devices. The circuit issolid state, including the firing threshold or switching portion, withall the inherent advantages of solid state devices.

Another possible control is to have external light intensityautomatically drive the normally stationary, nonrotatable window orwindows to an intermediately desired light transmission levelproportional to the light received, provided that the motor circuits areoverriden and not allowed to rotate, while the non-rotatable windows nowrotate by springloaded electro-magnetic means or solenoid. These notbeing illustrated, but also included by intent as a portion of thispresentation.

The objective of the drive system is to provide a friction drive againstone or more rotatable polarizing filters by a reversible motor orgearmotor, which allows for the advantage of a clutch type action in theevent of mechanical or electrical difficulties. One motor may directlydrive two polarizing filters at the same time, or more than two throughbelt friction drive, allowing slippage on one window at the end of itsDark or Light limit switch travel, while another syncs up, in the eventof an out of sync situation. As indicated, the motor friction drive maybe direct, or may use one or more belts, allowing the motor to beremotely located in order to avoid structural obstructions, or to gangdrive a series of windows.

One of the most important objectives is the use of Plexiglass II orsimilar ultra-violet ray retardant materials, glass, or coatings betweenthe light source and the polarizing filters. Most plastics and glassallow ultraviolet rays through, causing the polarizers to fade or bleachin such a short time and to such an extent as to become practicallyuseless.

Another particularly important objective is to proffer a temperaturecompensating circuit for the light sensor. As already mentioned, this isprobably as important for an automatic feature as is the capability ofthe circuit to react to varying external light intensities. In additionto temperature compensation, the circuit illustrated allows for a smallcircuit difference of only about one volt between relay pull-in anddrop-out, requiring a relatively non-sensitive relay. This is not to saythat a solid state device such as a silicon controlled rectifier couldnot be used in place of a relay. Also, although the circuit illustratedindicates an A.C. input, it is within the scope and intent of thisinvention also to operate on a DC. input, probably using a solar cell todrive a two stage transistor amplifier for altering the light signal tothe ultimate automatic polarization of the windows.

A final objective is to provide a mechanical or electrical demand meansfor biasing the light intensity level at which the light sensing devicewill accordingly react. This feature allows adjustment for individualcomfort insofar as the arbitrary level of too much glare is concernedduring automatic light sensing operation. Although not illustrated, itmay be readily understood that biasing of the incoming light signal mayeasily be accomplished mechanically simply by having an adjustable coverof sheet metal over the light sensing device, adjusted to block outlight as desired.

Although the aforementioned presents the major advantages, novelfeatures and objectives of this invention, it should be understood thatconstruction and arrangement of parts, as well as circuitry, areillustrative of the basic concepts and principles of the invention andare not to be construed as limiting in nature or scope, being withinlimits of the spirit of the invention.

It should also be contemplated within inventive intent and within thesame vein that certain parts, mechanical or electrical, may be deletedif not warranted by conditions necessitating their use, or requirement.

With the foregoing and further objects in view which shall materializeas the description is forged, the invention consists of additional noveldetails of circuitry, parts, and arrangement, hereinafter morespecifically described, illustrated, and pointed out in the claims.

Referring to the drawings:

FIG. 1 is a vertical section view constructed in accordance with thefeatures of my invention. This view is presented as though cut with someimaginary section line from a front elevational view. The purpose is toshow the various major parts in the most comprehensible manner possible;

FIG. 2 is a front elevational view taken along the direction indicatedby the arrows towards 22 in FIG. 1. The purpose of this view is to showthe more important parts of this invention and their actual respectivepositions;

FIG. 3 is a partial elevational view showing sufficient detail only toillustrate the principles of the removable window wiper;

FIG. 4 is a fragmental section view taken along the direction indicatedby the arrows towards 44 in FIG. 3. This view illustrates one of thefour wiper portions and fastening of the wiper assembly to the rotatingpolarizing filter assembly;

FIG. 5 is a schematic illustration of the principles of my invention. AnA.C. input is required to enable usage of the circuit represented. Thetemperature compensating, firing threshold portion of the circuit isrepresented by a group of components clustered in one area of theschematic for clarity. In retrospect, this highly sensitive portion ofthe circuit eliminates a need for a. light amplifier.

Reference is made to FIG. 1 which illustrates one possible generalarrangement of parts for use on aircraft. Working inboard, sunlightpasses through the opening in fuselage skin 10 and through outerwindow 1. Outer window 1 is pressure sealed between fuselage skin 10 andframe 11, and this window may be made of Plexiglass H, or other suitabletransparent material capable of blocking ultra-violet rays.

After passing through window I, the sunlight is enshrouded by frame 11,and then passes through stationary plastic polarizing window laminate 2,polarizing element 3, and plastic laminate 4, which are the laminatescomprising the inner, or acoustic window. Laminate 2 may be ofPlexiglass II instead of, or along with window 1, to block ultra-violetrays. Removable frame 13 pressure seals the stationary inner window inplace with gasket 12.

The sunlight then passes through the inner rotating polarizing filter,made up of plastic laminate 5 and plastic laminate 7, sandwiched overpolarizing element 6. The light continues through the clearance hole inmounting plate 22, is enshrouded by inner frame 23, subsequently passesthrough passenger scratch window 8, and finally emerges through theopening in reveal 9. All parts from the inner polarizing filter inboard,are mounted to reveal 9, with dust seal 27 adding to the shock absorbingend.

The amount of sunlight passing into the cabin is dependent on the rotaryposition of the inner polarizing filter about an approximate 90 arc.Reversible gearmotor 26 transmits torque through rubber friction drivering 18 on drive roller 17 to cause the inner polarizing filter torotate. Drive ring 18 could be eliminated if drive roller 17 was madeentirely of rubber.

In this view and in succeeding views and descriptive matter, maximumlight transmission occurs when lower limit switch 25 is tripped by trippin 16 and minimum light transmission occurs when upper limit switch 24is tripped. This is because stationary polarizer element 3 and rotatablepolarizer element 6 have their polarizing axis parallel in the formerposition, and crossed in the latter position.

Idler roller 15 is mounted in idler roller clevis 14 and exerts adownward force dependent on the spring rate of spring 19. Pivot bar 20pivots about pivot pin 21. Light sensor 28 receives light piped downthrough the inner rotating polarizing filter.

All of the laminates and windows are presumably made of clear,transparent plastic material for aeronautical safety reasons. Thelaminates sandwiching the polarizing elements provide structuralrigidity.

Referring to FIG. 2, it may be seen that pivot bar 20 will equalizespring forces on the two 19 springs to the two idler rollers. Thisaction causes equal wear on the two 15 idler rollers, acts as a shockmount, insures positive traction on the top edge of the inner polarizingfilter, prevents rattling, and insures positive traction on the lowerrollers. This spring force is transmitted through the inner polarizingfilter to provide a frictional force against rubber friction ring 18 ondrive roller 17 and rubber friction ring 18 on idler roller 29, and maybe adjusted by raising or lowering pivot pin 21. Rubber friction ring 18also aids in minimizing shock and vibration.

This view indicates that all of the windows, frames, seals, gaskets, andthe stationary polarizing window may be rectangular instead of round, orotherwise, so long as the viewing area is circumscribed by the rotatingpolarizing filter. This view did not include parts further outboardbecause further illustration of those parts would only obstruct clarityof the major portion of the device.

FIG. 3 shows the rubber window wiper 30 applied against the outboardside of passenger scratch window 8. As is indicated, the four wiper armswill cover the entire circular window area contacted each time thewindow rotates 90 from the light to dark or vice versa. A round windowconfiguration would obviously receive greater coverage than rectangular.Four small knobs, nearside in this view, hold the window wiper 30 to theinner polarizing filter.

FIG. 4 indicates the manner in which window wiper 30 is mounted to theinner polarizing filter. The four rubber knobs protrude throughclearance holes and hold the window wiper 30 in place by friction andgripping action under the heads of the knobs. If warranted byconditions, the window wiper could be exerted against a window on theother side of the inner polarizing filter, or both sides. Condensationis dropped from the end of the wipers, which describe a circular motionwithin the internal boundaries of frame 23.

FIG. illustrates an A.C. input to energize a two Window polarizingsystem. With the passenger override selector switch 45 in the PC, orPassenger Control position, the passenger control switches 44 and 46 maybe operated. The passengers do not have the capabilty of an automaticfunction with the circuit shown. Also, if two passengers try foropposite light functions at the same time, the one desiring Dark willsupersede the one desiring Light. This situation can be reversed byslight circuit alteration.

When the passenger wants the windows to go darker, he depressespassenger control switch 44 or 46 until a satisfactory degree ofdarkness is achieved. These switches are momentary in the dark or lightposition, and normally off. If he wishes the windows to go fully Dark,he maintains the switch in the dark position and limit switch trip pin16 will open upper limit switch 24 on both window assemblies, stoppingthe two reversible motors automatically when full Dark is reached by therotating inner polarizing filters. The inner rotating polarizing filteris indicated by 6 on the schematic, and the stationary polarizing windowis indicated by 3. Motor 26 is shown, but friction drive roller 17 isnot. Any number of polarizing window assemblies, override switches, orpassenger control switches can be electrically paralleled to the rest ofthe circuit shown. When either of the passenger control switches isdepressed in the dark position, relay 36 is energized by a half wavesignal through diode 34 and resistor 33. Half wave rectification allowspolarized capacitor 32 to function within this portion of the circuit asintended. Relay 36, resistor 33, and capacitor 32 create an LCR networkproviding a small time delay for actuating relay 36. This time delayprevents undue load on reversible motor 26 and gear train, if any, inthe event the passengers abusively play with the passenger controlswitches.

Gearmotors are advocated because they attenuate towards bettersynchronization at starting and stopping. Capacitor 31 is a motorstarting capacitor. If too many window adjustments are made withoutbringing the inner polarizing filters to the full Dark or Lightposition, they tend to get out of synchronization. That is, one windowcould actually get dark at the same time the other works itself to alight position because of difierences in motor start-up, stop, andsystem friction. As may be seen in this circuit, the inner polarizingfilters will at least re-sync any time they are directed to full Dark orLight. Synchronization is positive with this circuit.

In the light position of passenger control switch 44 or 46, relay 32coil is bypassed by the signal. This signal passes across relay 32contacts only and then through lower limit switch 25 to cause thewindows to get lighter. Limit switch trip pin 16 opens the circuit,automatically stopping motor 26 in the Light position when either of thepassenger control switches is constantly held closed.

All positions on override selector switch 45 are constantly maintainedpositions. As mentioned before, the PC position allows the passengers tocontrol the windows. The D for dark and L for light positions onoverride selector switch 45 work the same as the passenger controlswitches except, the control functions are normally maintained insteadof being momentary. The oif position on any switch immediately stops themotor when selected and facilitates operating the windows when locatedbetween the dark and light positions.

When A for automatic is selected, the window stay light until externallight becomes so bright as to actuate the temperature compensating,firing threshold portion of the circuit, causing the windows toautomatically go dark. The high sensitivity of this portion of thecircuit eliminates the need for an amplifier.

With A.C. across the circuit, diode 38 provides half wave rectificationto allow silicon controlled rectifier 39 to gate on as determined bylight intensity on light sensitlve device 28, and the setting ofpotentiometer 42. In this case, the light sensitive device is probably aphotocell.

Temperature stability of the automatic portion of the circuit isprovided by Balco wirewound resistor 40, Zener diode 43, and resistor41. Capacitor 35 acts as a filter for relay 37, which energizes the restof the Window circuitry.

Zener diode 43 acts as a reference with resistor 41 and the variousother components of this portion of the circuit 7 to maintain SCR39 at afiring threshold each half wave, when light intensity decreasesresistance across photocell 28 sufiiciently. Because of Balco resistor40, stability of the circuit is maintained such that the differencebetween pull-in and drop-out of relay 37 will be less than one voltthrough large temperature variations.

It is readily seen that a tendency to drift due to temperature variationon the coil of relay 37, is aborted by the isolated nature of theenergizing portion of the circuit. The firing threshold level may bepotentiometrically controlled by the pilot, hostess, and/ or as aseparate control of the passenger by varying potentiometer 42. One basiccircuit may control the polarizing windows on one or more sides of anairplane, building, structure, or other type vehicle.

The basic intended premise of the entire circuit is a solid statecircuit providing a polarizing window system which allows fortemperature stability, self-synchronization of all windows, automaticoperation with adjustable setting, a time delay for motor and mechanismprotection, an override capability, and a capability of stopping thewindows at any desired intermediate light transmittance level betweenLight and Dark. Although the solenoid or other similar electromechanicalautomatic control features are not shown, it is obvious that they may bereadily incorporated. It is also possible to utilize most of theconcepts described herein for use with a photoelastic polarizing means.Consequently, it is intended that they be included within the peripheryof the intent of my invention.

From the foregoing description, it is apperent that innumerable changesor modifications are possible within the electrical and mechanicalportions of this invention. Such changes are to be considered as comingwithin the scope and spirit of my invention as defined by the followingclaims.

I claim:

1. For use at the inside of an outer fixed window exposed to sunlightand contained in the outer wall of a passenger cabin, light polarizingstructure comprising first and second polarizing parallel windows spacedapart and both spaced separately from and inwardly from said fixedwindow in the path of light passing therethrough, one of said polarizingwindows being rotatable relative to the other polarizing window,mounting means separated from said outer window for supporting saidother polarizing window separately from said outer window and means forsupporting and controllably rotating the rotatable window.

2. Light polarizing structure according to claim 1, including an innerwall spaced from said outer wall and mounting an inner window spacedfrom and in the path 8 of light passing through said polarizing windowswhereby said polarizing windows are between said outer fixed window andsaid inner window.

3. Light polarizing structure according to claim 1, in which saidrotating means comprises a roller engaging and frictionally driving anarcuate edge of the rotatable window.

4. Light polarizing structure according to claim 2, in which saidrotating means comprises a roller engaging and frictionally driving anarcuate edge of the rotatable window.

5. Light polarizing structure according to claim 3, in which saidrotatable window is laminar and has its laminated edge engaged by saiddriving roller.

6. Light polarizing structure according to claim 5, in which saidrotatable window is circular and in edge engagement with idler rollersspaced about the window.

7. Light polarizing structure according to claim 6, in which said idlerrollers are spring urged against the window edge.

8. Light polarizing structure according to claim 7, in which saidrotatable window is vertically supported entirely by said driving andidler rollers.

9. Light polarizing structure according to claim 1, in which said outerwall is the wall of an aircraft cabin.

10. Light polarizing structure according to claim 2, in which saidspaced inner and outer walls are walls of an aircraft cabin and saidpolarizing windows are between said inner and outer walls.

References Cited UNITED STATES PATENTS 2,311,840 2/1943 Land 350-1592,423,321 7/1947 Hurley 350-459 2,989,787 6/ 1961 Smith 350-159 X3,159,844 12/1964 Haboush 350-159 X 3,290,203 12/1966 Antonson et al.3501 UX 3,281,965 11/1966 Irwin 350-159 X 3,377,118 4/1968 MacNeille350159 X 3,521,300 7/1970 Weiss 350-159 X FOREIGN PATENTS 196,148 7/1957 Austria 350-159 878,847 10/1961 Great Britain 350l59 DAVIDSCHONBERG, Primary Examiner P. R. MILLER, Assistant Examiner US. Cl.X.R. 350-156

